1 /* 2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 */ 7 8 #include <linux/ptrace.h> 9 #include <linux/module.h> 10 #include <linux/mm.h> 11 #include <linux/fs.h> 12 #include <linux/kdev_t.h> 13 #include <linux/fs_struct.h> 14 #include <linux/proc_fs.h> 15 #include <linux/file.h> 16 #include <asm/arcregs.h> 17 18 /* 19 * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25) 20 * -Prints 3 regs per line and a CR. 21 * -To continue, callee regs right after scratch, special handling of CR 22 */ 23 static noinline void print_reg_file(long *reg_rev, int start_num) 24 { 25 unsigned int i; 26 char buf[512]; 27 int n = 0, len = sizeof(buf); 28 29 for (i = start_num; i < start_num + 13; i++) { 30 n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t", 31 i, (unsigned long)*reg_rev); 32 33 if (((i + 1) % 3) == 0) 34 n += scnprintf(buf + n, len - n, "\n"); 35 36 /* because pt_regs has regs reversed: r12..r0, r25..r13 */ 37 reg_rev--; 38 } 39 40 if (start_num != 0) 41 n += scnprintf(buf + n, len - n, "\n\n"); 42 43 /* To continue printing callee regs on same line as scratch regs */ 44 if (start_num == 0) 45 pr_info("%s", buf); 46 else 47 pr_cont("%s\n", buf); 48 } 49 50 static void show_callee_regs(struct callee_regs *cregs) 51 { 52 print_reg_file(&(cregs->r13), 13); 53 } 54 55 void print_task_path_n_nm(struct task_struct *tsk, char *buf) 56 { 57 struct path path; 58 char *path_nm = NULL; 59 struct mm_struct *mm; 60 struct file *exe_file; 61 62 mm = get_task_mm(tsk); 63 if (!mm) 64 goto done; 65 66 exe_file = get_mm_exe_file(mm); 67 mmput(mm); 68 69 if (exe_file) { 70 path = exe_file->f_path; 71 path_get(&exe_file->f_path); 72 fput(exe_file); 73 path_nm = d_path(&path, buf, 255); 74 path_put(&path); 75 } 76 77 done: 78 pr_info("Path: %s\n", path_nm); 79 } 80 EXPORT_SYMBOL(print_task_path_n_nm); 81 82 static void show_faulting_vma(unsigned long address, char *buf) 83 { 84 struct vm_area_struct *vma; 85 struct inode *inode; 86 unsigned long ino = 0; 87 dev_t dev = 0; 88 char *nm = buf; 89 90 /* can't use print_vma_addr() yet as it doesn't check for 91 * non-inclusive vma 92 */ 93 94 vma = find_vma(current->active_mm, address); 95 96 /* check against the find_vma( ) behaviour which returns the next VMA 97 * if the container VMA is not found 98 */ 99 if (vma && (vma->vm_start <= address)) { 100 struct file *file = vma->vm_file; 101 if (file) { 102 struct path *path = &file->f_path; 103 nm = d_path(path, buf, PAGE_SIZE - 1); 104 inode = file_inode(vma->vm_file); 105 dev = inode->i_sb->s_dev; 106 ino = inode->i_ino; 107 } 108 pr_info(" @off 0x%lx in [%s]\n" 109 " VMA: 0x%08lx to 0x%08lx\n", 110 vma->vm_start < TASK_UNMAPPED_BASE ? 111 address : address - vma->vm_start, 112 nm, vma->vm_start, vma->vm_end); 113 } else { 114 pr_info(" @No matching VMA found\n"); 115 } 116 } 117 118 static void show_ecr_verbose(struct pt_regs *regs) 119 { 120 unsigned int vec, cause_code; 121 unsigned long address; 122 123 pr_info("\n[ECR ]: 0x%08lx => ", regs->event); 124 125 /* For Data fault, this is data address not instruction addr */ 126 address = current->thread.fault_address; 127 128 vec = regs->ecr_vec; 129 cause_code = regs->ecr_cause; 130 131 /* For DTLB Miss or ProtV, display the memory involved too */ 132 if (vec == ECR_V_DTLB_MISS) { 133 pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n", 134 (cause_code == 0x01) ? "Read" : 135 ((cause_code == 0x02) ? "Write" : "EX"), 136 address, regs->ret); 137 } else if (vec == ECR_V_ITLB_MISS) { 138 pr_cont("Insn could not be fetched\n"); 139 } else if (vec == ECR_V_MACH_CHK) { 140 pr_cont("%s\n", (cause_code == 0x0) ? 141 "Double Fault" : "Other Fatal Err"); 142 143 } else if (vec == ECR_V_PROTV) { 144 if (cause_code == ECR_C_PROTV_INST_FETCH) 145 pr_cont("Execute from Non-exec Page\n"); 146 else if (cause_code == ECR_C_PROTV_MISALIG_DATA) 147 pr_cont("Misaligned r/w from 0x%08lx\n", address); 148 else 149 pr_cont("%s access not allowed on page\n", 150 (cause_code == 0x01) ? "Read" : 151 ((cause_code == 0x02) ? "Write" : "EX")); 152 } else if (vec == ECR_V_INSN_ERR) { 153 pr_cont("Illegal Insn\n"); 154 } else { 155 pr_cont("Check Programmer's Manual\n"); 156 } 157 } 158 159 /************************************************************************ 160 * API called by rest of kernel 161 ***********************************************************************/ 162 163 void show_regs(struct pt_regs *regs) 164 { 165 struct task_struct *tsk = current; 166 struct callee_regs *cregs; 167 char *buf; 168 169 buf = (char *)__get_free_page(GFP_TEMPORARY); 170 if (!buf) 171 return; 172 173 print_task_path_n_nm(tsk, buf); 174 show_regs_print_info(KERN_INFO); 175 176 show_ecr_verbose(regs); 177 178 pr_info("[EFA ]: 0x%08lx\n[BLINK ]: %pS\n[ERET ]: %pS\n", 179 current->thread.fault_address, 180 (void *)regs->blink, (void *)regs->ret); 181 182 if (user_mode(regs)) 183 show_faulting_vma(regs->ret, buf); /* faulting code, not data */ 184 185 pr_info("[STAT32]: 0x%08lx", regs->status32); 186 187 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit : "" 188 if (!user_mode(regs)) 189 pr_cont(" : %2s %2s %2s %2s %2s\n", 190 STS_BIT(regs, AE), STS_BIT(regs, A2), STS_BIT(regs, A1), 191 STS_BIT(regs, E2), STS_BIT(regs, E1)); 192 193 pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n", 194 regs->bta, regs->sp, regs->fp); 195 pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n", 196 regs->lp_start, regs->lp_end, regs->lp_count); 197 198 /* print regs->r0 thru regs->r12 199 * Sequential printing was generating horrible code 200 */ 201 print_reg_file(&(regs->r0), 0); 202 203 /* If Callee regs were saved, display them too */ 204 cregs = (struct callee_regs *)current->thread.callee_reg; 205 if (cregs) 206 show_callee_regs(cregs); 207 208 free_page((unsigned long)buf); 209 } 210 211 void show_kernel_fault_diag(const char *str, struct pt_regs *regs, 212 unsigned long address) 213 { 214 current->thread.fault_address = address; 215 216 /* Caller and Callee regs */ 217 show_regs(regs); 218 219 /* Show stack trace if this Fatality happened in kernel mode */ 220 if (!user_mode(regs)) 221 show_stacktrace(current, regs); 222 } 223 224 #ifdef CONFIG_DEBUG_FS 225 226 #include <linux/module.h> 227 #include <linux/fs.h> 228 #include <linux/mount.h> 229 #include <linux/pagemap.h> 230 #include <linux/init.h> 231 #include <linux/namei.h> 232 #include <linux/debugfs.h> 233 234 static struct dentry *test_dentry; 235 static struct dentry *test_dir; 236 static struct dentry *test_u32_dentry; 237 238 static u32 clr_on_read = 1; 239 240 #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT 241 u32 numitlb, numdtlb, num_pte_not_present; 242 243 static int fill_display_data(char *kbuf) 244 { 245 size_t num = 0; 246 num += sprintf(kbuf + num, "I-TLB Miss %x\n", numitlb); 247 num += sprintf(kbuf + num, "D-TLB Miss %x\n", numdtlb); 248 num += sprintf(kbuf + num, "PTE not present %x\n", num_pte_not_present); 249 250 if (clr_on_read) 251 numitlb = numdtlb = num_pte_not_present = 0; 252 253 return num; 254 } 255 256 static int tlb_stats_open(struct inode *inode, struct file *file) 257 { 258 file->private_data = (void *)__get_free_page(GFP_KERNEL); 259 return 0; 260 } 261 262 /* called on user read(): display the couters */ 263 static ssize_t tlb_stats_output(struct file *file, /* file descriptor */ 264 char __user *user_buf, /* user buffer */ 265 size_t len, /* length of buffer */ 266 loff_t *offset) /* offset in the file */ 267 { 268 size_t num; 269 char *kbuf = (char *)file->private_data; 270 271 /* All of the data can he shoved in one iteration */ 272 if (*offset != 0) 273 return 0; 274 275 num = fill_display_data(kbuf); 276 277 /* simple_read_from_buffer() is helper for copy to user space 278 It copies up to @2 (num) bytes from kernel buffer @4 (kbuf) at offset 279 @3 (offset) into the user space address starting at @1 (user_buf). 280 @5 (len) is max size of user buffer 281 */ 282 return simple_read_from_buffer(user_buf, num, offset, kbuf, len); 283 } 284 285 /* called on user write : clears the counters */ 286 static ssize_t tlb_stats_clear(struct file *file, const char __user *user_buf, 287 size_t length, loff_t *offset) 288 { 289 numitlb = numdtlb = num_pte_not_present = 0; 290 return length; 291 } 292 293 static int tlb_stats_close(struct inode *inode, struct file *file) 294 { 295 free_page((unsigned long)(file->private_data)); 296 return 0; 297 } 298 299 static const struct file_operations tlb_stats_file_ops = { 300 .read = tlb_stats_output, 301 .write = tlb_stats_clear, 302 .open = tlb_stats_open, 303 .release = tlb_stats_close 304 }; 305 #endif 306 307 static int __init arc_debugfs_init(void) 308 { 309 test_dir = debugfs_create_dir("arc", NULL); 310 311 #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT 312 test_dentry = debugfs_create_file("tlb_stats", 0444, test_dir, NULL, 313 &tlb_stats_file_ops); 314 #endif 315 316 test_u32_dentry = 317 debugfs_create_u32("clr_on_read", 0444, test_dir, &clr_on_read); 318 319 return 0; 320 } 321 322 module_init(arc_debugfs_init); 323 324 static void __exit arc_debugfs_exit(void) 325 { 326 debugfs_remove(test_u32_dentry); 327 debugfs_remove(test_dentry); 328 debugfs_remove(test_dir); 329 } 330 module_exit(arc_debugfs_exit); 331 332 #endif 333